1. Field of the Invention:
The invention relates to a method for removing soot particles from an exhaust gas, in particular of an internal combustion engine. The invention also relates to a collecting element suitable for that purpose, in particular one which can be regenerated and can be installed in a pipe, e.g. in an exhaust line of a motor vehicle. The invention additionally relates to a system having a collecting element.
In addition to gaseous constituents, the exhaust gas of an internal combustion engine also contains particles. Those particles enter the environment directly with the exhaust gas, which is undesirable, or they are often deposited somewhere in the exhaust system, with the result that they are then emitted in the form of a cloud of particles in the case of load changes, for example.
It is conventional to use filters to collect the particles. However, the use of closed filter systems entails two significant disadvantages: on one hand, those filters can become clogged and, on the other hand, they cause an unwanted pressure drop. If no filters are used, those particles which do not pass directly into the environment may be deposited on the coating of an installed catalytic converter which is provided for purifying the exhaust gas of other polluting components, where they lead to poisoning or at least to a reduction in the catalytically active surface area. As part of ever-stricter laws to protect the environment, emissions of pollutants and particles are to be reduced further. In addition to the removal of particles, the reduction of nitrogen oxides also plays an important part in exhaust-gas purification. German Published, Non-Prosecuted Patent Application DE 42 03 807 A1 has disclosed a device for that purpose, in which an oxidizing agent is injected and mixed with the exhaust gas.